Most toilets in use today, consist of two main parts; an upper part which holds water, referred to as a tank section, and a lower part consisting primarily of a bowl with a volume of water which is designed to receive human waste products. Once the waste products have been deposited in the bowl, they are removed by releasing the water held in the upper tank section into the bowl. The released water removes the waste products to a collection system, such as a sewer system or a septic tank, and then refills the bowl so that there remains standing a volume of water. Waste products consists of solid and liquid wastes and in presently available toilets, one full flush is utilized to carry away both solid and liquid wastes, even when there is only liquid waste in the toilet bowl. In these standard toilets, a full complete flush is effected with each flush and the total contents of the water in the tank section is drained into the bowl and then out into the sewer system.
One of the most often used toilet flushing systems comprises a ball-cock valve assembly that controls the inlet of water into the tank section. A float ball is connected to the ball-cock valve by means of a float arm. As the toilet tank fills with water, the buoyant float ball rises in the tank section. The motion of the float ball is transmitted to the ball-cock through the float arm until at a predetermined water level the ball-cock assembly shuts off the water inlet to the tank. This corresponds to a generally horizontal position of the float arm. In most toilets, the water level in the water tank may be adjusted by means of a screw set mechanism provided in the ball-cock assembly. This adjustment, however, is limited in range and requires that the tank lid be lifted to obtain access to the ball-cock. Once the water level in the tank is set, the adjustment is usually thereafter ignored. The same volume of water is therefore discharged from the tank every time that the flushing system is tripped, regardless of the volume which may be actually required to successfully flush the toilet.
It is a well known fact that the largest use of water in most households and in many office buildings is for flushing toilets. Because flushing is carried out with the full capacity of the water in the water tank, the water usage is wasteful and is not required. Considerable interest has been centered on reducing the water used when toilets are flushed, especially at times and in places when there is a water deficiency or periods of drought.
Several water saving methods have been used to conserve water during the toilet flushing operation. One such method has been to deposit a filled water bag or a solid object, such as a brick, in the water tank to displace an equivalent volume of water in the tank, to thus reduce the volume of water consumed with each flushing. Another common method is to lower the float valve to allow the ball-cock valve to close at a reduced water level. These methods to conserve water in many cases are self-defeating, in that, the effectiveness of the flush is diminished and it may be necessary to flush twice to effect a sanitary flush. Additionally, such methods represent a compromise in that the volume of water is set and is not readily adjustable.
Other flush saving methods have included modifying a flapper valve and a tank ball valve by inserting into the valve various types of foam fillers. An analysis of this method, conducted by the applicant, determined that open-pore foam partially functioned; closed-pore foam would not work at all as the inside of the foam would not absorb the water. The analysis further disclosed the following.
The specific gravity of water is 1.00 while the specific gravity of the foam and the neoprene rubber is between 0.96 and 1.1. Therefore, the foam modified valve assembly is slightly over the specific gravity of water. The problem here is to be sure that the valve is completely filled with foam and that the foam is completely filled with water. If the smallest air space is present, the slight margin of weight is overcome and the valve will float, thus defeating the requirement for a quick closing valve. Further investigation revealed that the only way to completely fill the foam was by squeezing and releasing it under water. The foam never completely filled when installed (open side down) as air is trapped inside the valve and the foam sponge cannot fill without displacing the trapped air.
The investigation also revealed that often the valve remains "seated" in the water delivery port of the tank section for a period of time. When this period is approximately eight hours, the water drains out of the sponge and into the open space under the tank and the water pressure "head" deforms the valve to conform to the seat. This condition squeezes out some of the water in the sponge. With this additional loss of water the specific gravity of the valve is reduced to much less than water. Thus, when the valve is actuated after the seating period, the valve floats, defeating the water saving purpose of the invention. Once the water has drained out, the valve must be removed to refill the sponge because in the floating position, only half of the valve is submerged and the trapped air will not allow the sponge to refill. The specific gravity at this point, is less than 1.0 and therefore, the valve continues to float negating the water saving feature.
Solid foams were also checked and where determined not to be feasible. The tank valve seats are of two types: metal rings or "cast in" the porcelain. Both are subject to out-of-round conditions due to manufacturing tolerances and from nodules grown from the salts in the water. Both of these conditions require that the valve be soft enough to conform to the valve seat. When a solid foam is used, the weight of the foam interferes with the required deformation. The solid foam also presents the same problem, as stated above, in filling the solid foam completely and with the water draining out when the valve is closed for an extended period of time.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention however, the following U.S. patents were considered related:
______________________________________ U.S. Pat. No. INVENTOR ISSUED ______________________________________ 4,837,867 Miller 13 June 1989 4,700,413 Lopez 20 October 1987 4,483,024 Troeh 20 November 1984 4,364,129 Schonger 21 December 1982 4,268,924 Price et al 26 May 1981 4,216,555 Detjen 12 August 1980 ______________________________________
The Miller patent discloses a dual flush system for toilets to effect a full flush or a partial flush of the toilet to carry away liquid wastes. The system functions by partially opening the main valve, located in the water holding tank of the toilet, for a period of time that is determined by the operator. When the valve is opened slightly, downward pressure on the valve and suction forces the water passing between the valve and valve seat to exert a downward force on the valve that causes the valve to pull back into a closed position after opening. Only when the valve is raised to a position where its buoyancy exceeds the downward pressure is a full flush effected. The system includes the means to limit the upward lifting of the valve by limiting the lengthwise travel of a cord attached to the valve. The cord is attached on its other end to a flush handle and lever.
The Lopez patent discloses a toilet flushing mechanism that provides high and low water volume selectability. The invention consists of an articulated float arm that is normally bent at an angle by a detent mechanism to maintain a low water level in the toilet water tank. A linkage is provided to the exterior of the tank for releasing the detent mechanism. When so released, the buoyant float straightens the arm thereby admitting additional water into the tank to obtain a more vigorous flushing action.
The Troeh patent discloses a variable flush for a toilet water tank wherein the valve is operated by the same toilet trip lever as the usual single level types. The operational differences, presented by the invention, is that a light pressure on the toilet trip handle causes the two-level flush valve to yield a small flush whereas a heavier pressure will cause a full flush. The invention includes a first float connected to the outer end of the valve arm to maintain the valve in an open position until the water level falls below a predetermined level. A second float is carried on a float arm pivoted intermediate its ends to the support.
The Schonger patent discloses a toilet flush system that allows a user to manually control the amount of water used for a toilet flush. The system uses a modified flapper valve, a tank ball valve or other type valves to control the closing of a reservoir outlet at selected times prior to or upon completion of the normal flush cycle. The tank ball or flapper valve is modified to overcome its buoyancy such that it rapidly closes the tank reservoir to thereby terminate the flush cycle when the handle of the toilet is released. By maintaining the handle in the operated position, the individual flush cycle can be controlled dependent on the waste to be disposed of. The buoyancy of the valve is overcome by inserting a water absorbing material, such as a sponge, into the valve, when the valve is primed, the sponge increases the weight of the valve.
The Price patent discloses a toilet flushing apparatus that incorporates an inventive water control valve that is used in a syphon-operated closet bowl flush tank having an inverted bell containing a liftable plunger disc to initiate syphon action the valve allows a user to select between a light or a heavy flush. A light flush is derived from an initial operation followed by a quick release. A heavy flush is derived from an initial operation which is then sustained. To fit the valve to an existing inverted bell, a hole is cut into the top of the bell and the valve is lowered through the hole.
The Detjen patent discloses a dual-flush toilet system that provides either a full flush or a partial flush at the option of the user. When a full flush is desired, the flush handle is actuated normally; if a partial flush is desired, the handle is held in a depressed condition for two to three seconds. The partial flush is produced when a buoyant reseating weight floats down with the falling level of the liquid in the tank. The weight depresses the flush ball and prematurely reseats in its outlet seat when only part of the liquid has been discharged from the tank. The reseating weight is provided with a latch actuated by the flush handle. For a full flush, the latch is released but is immediately re-engaged before the reseating weight moves downwardly in the tank.